Abstract: With the improvement of living standards, the electromagnetic environment becomes more and more important in recent years. In the transmission project, the electromagnetic environment is closely related to the corona characteristics. Therefore, it is particularly important to study the corona discharge characteristics of the UHV transmission project to guide the project construction. The corona discharge characteristic of the conductor is one of the key factors affecting the electromagnetic environment of the project. Besides the structure and manufacturing process of conductor, the distance from the transmission line to the ground is also an important factor causing the change of the discharge characteristics of the wire. In order to obtain corona discharge characteristics of conductors with different heights to ground and correction methods for inception corona voltage of conductors with different heights to ground, corona test were carried out in Ultra-high Voltage Test Base in Wuhan with ultraviolet image apparatus. the corona test of conductors of JL/G1A-1250/100 and JL/G1A-1250/70 at different heights to ground were carried out, one single conductor, bundle distance 500mm, 6-bundle conductor and distance 550mm, 8-bundle conductor were tested separately. Conductors type were JL/G1A-1250/100 and JL/G1A-1250/70. one singe conductor, which length is 16m, 6-bundle conductor, which length is 16m and bundle spacing is 500mm, 8-bundle conductor, which length is 16m and bundle spacing is 550mm, Three kinds of wires were tested separately in different heights to ground. The results show that Under DC positive voltage, the corona inception voltage for conductors increased with the rise of the height to ground, different bundle distances, bundle conductors and one single conductor corona discharge characteristics have some differences; The corona inception voltage between single conductor and bundle conductors have certain functional relationship. By establishing the functional relationship between them, the corona inception voltage of bundle conductors can be calculated by the corona inception voltage value of a single conductor, and the value of correction errors can be controlled at less than 7%.